Data storage devices commonly have a recording head that includes a read transducer that reads information from a data storage medium and a write transducer that writes information to a data storage medium.
In magnetic data storage devices such as disc drives, a magnetoresistive (MR) sensor such as a Giant Magnetoresistive (GMR) sensor or a Tunnel Junction Magnetoresistive (TMR) sensor has traditionally been employed as the read transducer to read a magnetic signal from the magnetic media. The MR sensor has an electrical resistance that changes in response to an external magnetic field. This change in electrical resistance can be detected by processing circuitry in order to read magnetic data from the adjacent magnetic media.
The ever increasing need for increased data storage necessitates ever increasing data density in magnetic data storage devices. One way to increase data density is to decrease the size and spacing of magnetic bits recorded on the media. The read sensor is generally sandwiched between a pair of magnetic shields, the spacing between which determines the bit length, also referred to as gap thickness. Sensors such as GMR or TMR sensors are constructed as a stack of layers all formed upon one another sandwiched between the magnetic shields. Accordingly, the ability to reduce the spacing between shields with such a sensor structure is limited.